System of electric-motor control.



PATENTED JULY '7. 1908.

H. D. JAMES.

SYSTEM OF ELECTRIC MOTOR CONTROL.

APPLICATION FILED NOV. 3, 1906.

INVENTOR WiTNESSES:

ATTORNEY lJNlTED HENRY l). Lilli. S, )l ll'lTSBURG, EENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC MANUFAG'lUBl"G COMPANY, A CORPORATION OF PENNSYLVANIA.

rains earner FFlC,

SYEl'EEM OF ELEGTEIG-MQTOR CONTROL.

Cele. ililfih lfitk Specification of Letters Patent. Patented July '7, 1908.

Application filed. November 3, 1906. Serial No. 341,890.

Z'o eZl wh am it'may concern: T tion of the, starting resistance included in the ts. it lmown that I, Hnivnr l}. la-Mega motor circuit. is. determined by a series of citizen of the United btates, and. a resident of manually-operated switches 7, S, 9, and

Fittshurg, in the county of Allegheny and 1.1, switches 8, 9", 1t) and 11 being provided State ofPennsylvania, have invented a new with electro-magnetically controlled means useful Improvement in Systems of Ele6- for preventing their closure, which con1- tric-Motor Control, of which the following is prises stationary core members 12, 13, 14 and 60 aspecihcation. f 3.5, and pivotally mounted pawls 16, 17, 18 a -M invention relates to controlling means and 19. When the switches are ooen, the for e ectric motors, and has special reference pawls normally occupy such positions that "to-systems or devices which are adapted for closure of the switches is prevented. each s arting relatively large motors. pawl being so held by a spring 20 or by.65

"Ti lie object of my invention is to provide ,gravity that its outer end engages a projecmeans that shall be simple and durable in tion 21 on the corresponding switch. The construction and effective in operation fer cores 12, 13, i4 and 15 are severally proehntrolling the starting resistances of relavided with magnet windings 22, 23, 24 and tivelylarge electric motors and for eliminat 25 which, when energized, act in opposition ing the pos'silzilityor, injuring the motor tov the springs 20 to release the pawls from windings by increasing the applied voltage engagement with the projections 21 and contoo rap1dly. sequently permit the manual closure of the For starting relatively large electric moswitches. rs, a plurality of switches for gradually re- The switches 7 8, 9 and 10 are provided tlucing resistance in the motor circuit, with auxiliary contact terminals 26, 27, 28

they were successively closed, have and 2.9, which are ada ted to engage stationtimcs been'utilized in lieu of the ordinary ary contact termina s 31, 32, 33 and 34, forms of starting rheostats usually employed when the switches are closed. The switches" with motors of the smaller sizes. The sev 8, 9, 10 and 11 are further provided with oral switches comprised in a starter or" the auxiliary contact terminals 36, 37, 38 and 39 store-said class" have sometimes been me which are adapted to engage stationary conchanically or electrically interlocked in order tact terminals 40, 41, 42 and 43 when the to. prevent the closure of the switches in switches are open. The ends and a plurality other than a predetermined order, or to auof intermediate points in the starting resisttomatically interrupt the motor circuit in since 6 are connected to stationary switch case the sw'tches were so closed. contact terminals 44, 45, 46, 47 and 48 According to my present invention, It not which are respectively engaged by the switch only prevent the closure of the. control blades. switches in other than a predetermined The electrical connections between the o'rdenbut also so arrange the systemthat it several magnet coils are such that the pawls becomes a physical impossibility for an at- 16, 17 18 and 19 are successively released as tendantto decrease the resistance of the 1100- the switches 7, 8, 9 and 10 are closed, protor circuit too rapidly by successively closing vided the current in the motor circuit does the switches regardless of the current flowing not exceed a predetermined amount. In in. the motor circuit. case such predetermined amount is exceeded,

The single figure of the accompanying the release action is delayed by a limiting dedrawingis a diagrammatic view of a system vice 49. of electric motor control arranged in accord The 0 oration of the system is as folance with my invention. lows :E ectrical energy is supplied, when Referring to the drawin electrical energy the switch 7 is closed, through conductor 1 a may besupplied from any convenient source series magnet coil 50 of the limiting device through line conductors 1 and 2 to an elec- '49, starting resistance 6, switch terminal 44, trio motor 3 which comprises an armature 4 and the movable member of switch 7 t0 the and a field magnet 5 and which is provided. armature 4 of the motor 3, from which point with a starting resistance 6. The propor circuit is completed through the line-concircuit 51.

ductor 2. The characteristics of the starting resistance 6 will, of course, be determined by the size of the motor and the conditions of load under which it is started and, if the motor current exceeds a predetermined amount, the limiting device 4-9 will be actuated by the series coil 50 and will interrupt an auxiliary As soon as this limiting device is circuit is completed from the line con- 1, through said device, auxiliary conductor 51, contact terminals 26 and 31, conductor 52, magnet winding 22, contact terminals 40 and 36, and conductor 53 to the opposite line conductor 2. The magnet winding 22, when energized, actuates the pawl 16 in opposition to the spring 20, so that the switch 8 may be closed. When the switch 8 is closed the magnet windin 22 will be deenergized but the switch will then be independent of the pawl 16, so that its release at this point will have no effect. Energy will now be supplied, provided the limiting device is closed, through contact terminals 27 and 82, conductor 54, magnet windin 23, contact members 4]. and 37, and conductor 53 to the line conductor The winding 23, when energized, actuates pawl 1? so that the switch 9 may be closed. in a similar manner, the pawls 18 and 19 may be successively actuated so that the switches if) and 11 may be closed.

It will be ob "ed that the closure of the switches is cor d to a predetermined se quence and that the closure of each switch is dependent upon the limiting device, so that the starting resistance cannot be short-circuitcd too rapidly. As each of the switches 8, 9 and 10 is closed a greater portion of the resistance 6 is excluded irom the motor cir cult and, when the switch 11 is closed, the entire resistance is finally short-circuited.

The motor starter of my present invention is equally applicable to alternating and direct current circuits and for voltage as well as rheostatic control, and I desire that only such limitations be imposed as are indicated in the appended claims.

I claim as my invention:

1. A motor-starting device comprising a series of manually operated switches, electrically released mechanical means for conlining their closure to a predetermined. sequence and electrical means for delaying their closure.

2. A motor-starting device comprising a series of manually operated independent accelera-ting switches, electrically released me chanical means for preventing the closure of closed, ductor the same except in a definite order, and electrical means for delaying the closure of each until the automatic. fulfilment of predetcrmined conditions.

3. The combination with an electric n10- tor, a starting resistance therefor, and a plurality of manually operated accelerating switches for scenes switches, of electricallyreleased mechanical means for preventing the closure of the switches except in a predetermined order, and electrical means for delaying the closure of each switch until the motor current fallsbelowa predetermined amount.

4. The combination with an electric motor, a starting resistance therefor, and a plurality of manually operated independent switches for bridging sections of the resistance, of electrically released mechanical means for preventing the closure of the switchesin other than a definite order, and electrical means for preventing the closure of any resistance-reducing switch until the current in the motor circuit falls below a predetermined amount.

5. The combination with an electric motor, a starting resistance therefor, a plurality of manually operated independent controlling the resistance of the motor" circuit, a limiting device and an actuating coil therefor which is connected in said circuit, of electrically released mechanical means for preventing the closure of the switches other than in a predetermined order, and means dependent upon the limiting device for delaying the closure of the switches.

6. The combination with an electric motor, a starting resistance therefor, a lurality of manually operated independhnt switches for controlling the resistance in the motor circuit, and a limiting device that is actuated by the motor current; of mechanical stops or awlsfor preventing the closure of the manua ly operated switches other than in a predetermined order, and means dependent upon the limiting device for delaying the closure of the switches.

7. A motor-starting device comprising a series of manually operated switches, electro magnetically actuated pawls for confining their order of closure to a predetermined se quence and for delaying their closure until the motor current falls below a predetermined amount. I

S. The combination with an electric motor, a starting resistance, and a plurality of manually operated accelerating switches, of means comprising mechanical stops or pawls for preventing the closure of the switches except in a predetermined order, actuating magnets for said pawls which may only be energized when the current in the motor circuit falls below a predetermined amount.

The combination with an electric motor: a starting resistance, a plurality of manually operated accelerating switches, a limit ing device which is energized when the current in the-motor circuit exceeds a predetermined amount, of means comprisin mechanical stops or pawls for preventing theclosure of the switches except in predetermined or der, and actuating magnets which may only 5 chemical means for positively confining their Witnesses:

be energized when permitted by the limiting deviee.

In testimony whereof, I have hereunto subscribed my name this 31st day of Octo 10. A motor-starting device com rising e1 ber, 1906 series of-manu'elly-eperated swite es, me- HENRY D. JA \1ES.

closure to a predetermined. sequence, and EDWIN LEHR, ether means for delaying their closure, BIRNEY HINES. 

